Kristen Stewart on her upcoming film, Ang Lee, and what scared her on the set.

With her first red carpet appearance with girlfriend Ai??St Vincent, akaAi?? Anne Clark, making their relationship official, actress Kristen Stewart has been hogging headlines and social media timelines. The Twilight saga star plays Kathryn, sister of the protagonist, a soldier named LynnAi??(Joe Alwyn),Ai??in her next film Billy Lynnai??i??s Long Halftime Walk. She also shares screen space withAi??Vin Diesel and Steve Martin. The war dramaai??i??based on a book of the same name by Ben Fountainai??i??is directed by Academy Award-winner Ang Lee and is set for release next week. Here, the 26-year-old talks about working with Lee and on understanding her character.

What was it about this project that made you want to be a part of it?
I wouldnai??i??t want to sound super simplistic in saying, ai???I probably would have done anything with Angai??i??. I grew up on his movies. When it came to be, IAi??wasAi??pretty traditional. I read the script and I loved the opportunity to do something really whole and, over the course of four days, I knew that I needed to endow this movie with a lot of what it says in a really short period of time.

Tell us more about the relationship between your character and the protagonist?
Thereai??i??s an understanding that allows you to love. SomebodyAi??that sheAi??(Kathryn)Ai??loves more than she has loved anyone, comes back, completely unk-nown. The one thing that kind of tips me out about it is that thereai??i??s such a crazy, remote relationship to this, because thatai??i??s the only one we could have, and rather than trying to understand him, she wants him to understand himself. Like ai???just think for yourself, understand yourself, Iai??i??m not going to push you in any direction because I havenai??i??t walked in your bootsai??i?? so to speak. There was one scene where you see him deciding to take someoneai??i??s life. I couldnai??i??t watch it. Iai??i??ve seen people kill others in movies, but not in this way. In the scariest sense, it lodges you in your body in the most visceral way, in regards to something that may not feel so visceral to us now. Thatai??i??s what I think the movie does and Iai??i??m really thankful to be a part of that.

Since the movie Ai??is the first ever to be shot in super-high-resolution 3D (at 120 frames per second), as an actor how conscious were you about this media?
Itai??i??s crazy because half of you feels disconnected because what youai??i??re used to as actors is being observed from a somewhat different perspective and having an unbreakable connection with another person thatai??i??s looked at from the outside. And then the other half feels more intimate because youai??i??re engaging with something head on and you know that youai??i??re being looked on directly, and that is a really vulnerable feeling. Itai??i??s a very different feeling and itai??i??s not one that Iai??i??ve ever had before.

Actor Alwyn on getting under the skin of the lead character (Billy Lynn).
I was called a month before, so the timing was pretty short. But the seven of us did two weeks of boot camp in Atlanta. We had no contact with the outside world. Every day we went through training which was incredibly intense and pushed us to the breaking point.Ai??But it also brought us together as a unit. Also, Iai??i??m British and Billy is American, but ultimately, even though itai??i??s within this bigger framework of American prejudice and commentary on the war, itai??i??s a very human story about a young boy finding out who he is in the world, where he wants to go and where he belongs. Thatai??i??s what I tried to holdAi??on to.